pythom import

[aben20807]

.
├── main.py
└── pkg
    ├── __init__.py
    ├── mod_a.py
    └── mod_b.py

main.py

from pkg.mod_b import b

if __name__ == '__main__':
    b()

pkg/mod_a.py

def a():
    print("a")

pkg/mod_b.py

from pkg.mod_a import a

def b():
    a()
    print("b")

if __name__ == '__main__':
    b()

commands:

$ python3 main.py 
a
b

$ python3 pkg/mod_b.py
a
b

[aben20807]

https://medium.com/pyladies-taiwan/python-%E7%9A%84-import-%E9%99%B7%E9%98%B1-3538e74f57e3